کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4531822 1626123 2014 10 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Distribution of planktonic cnidarians in response to South Atlantic Central Water intrusion in the South Brazilian Bight
ترجمه فارسی عنوان
توزیع نانوذرات پلانکتونی در پاسخ به نفوذ آب های مرکزی آب آتلانتیک جنوبی در محدوده ی برزیل جنوبی
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات زمین شناسی
چکیده انگلیسی


• Cold oceanic bottom intrusion and associated environmental changes were clear.
• The planktonic cnidarian assemblage was highly influenced by the oceanic bottom intrusion.
• Coastal species decreased their abundance and extent during intrusion periods.
• Oceanic species tended to increase abundance and distribution during intrusion.

Five oceanographic cruises were made between November 2005 and June 2006, sampling a cross-shelf transect off the South Brazilian Bight (SBB; 26°46′S) to follow the seasonal development of the South Atlantic Central Water (SACW) intrusion over the shelf and its influence on the assemblage of planktonic cnidarians. An onshore wind-driven bottom intrusion of the SACW was clearly perceptible, reaching the coast in January. From March onward, the SACW influence was gradually displaced seaward due to wind and tidal mixing. By late June the SACW influence was offshore and the inshore was dominated by low-salinity waters (<34.5). The abundance, distribution, and general taxonomic composition of both medusae and siphonophores were strongly influenced by the onshore intrusion of the SACW. An inshore–offshore gradient was clear. The Canonical Correspondence Analysis suggested that coastal species – dominated by Liriope tetraphylla, actinula larvae and Muggiaea kochi – were mostly related to food availability and a vertically mixed environment inshore, and their abundance and extent were reduced during intrusion periods. In contrast, species with offshore affinities tended to increase their abundance and distribution during intrusion periods, and were mostly related to the presence of thermal stratification and a deep chlorophyll maximum layer. Most of these offshore species, such as Aglaura hemistoma, Rhopalonema velatum and many calycophorans, are associated with the warm upper layer. However, high concentrations of large (>20 mm in diameter) Solmaris corona were observed exclusively in cold waters, suggesting this medusa is a SACW indicator.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Continental Shelf Research - Volume 89, 15 October 2014, Pages 93–102
نویسندگان
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